Its usefulness was demonstrated extensively during the response to the Fukushima nuclear power plant (NPP) accident in March-May 2011. = ,Īirborne gamma spectrometry is one of the primary techniques used to define the extent of ground contamination after a radiological incident. The process of establishing such a line, as well as necessary ground truth measurements, is described in this document. In order to verify and validate individual aerial systems, the calibration line needs to be characterized in terms of ground truth measurements This is especially important if the contamination is due to short-lived radionuclides. Such a line should be flown periodically in order to normalize data collected from different aerial acquisition systems and that are potentially flown more » at different flight altitudes and speeds.
However, because production of a single, consistent map product depicting the ground contamination is the primary goal, it is critical to establish a common calibration line very early into the event. During a large-scale radiological event, multiple flights may be necessary and may require use of assets from different agencies. This is done using conversion coefficients derived from calibration flights. To provide useful information to decision makers, the count data, expressed in counts per second (cps), need to be converted to a terrestrial component of the exposure rate at 1 meter (m) above ground, or surface activity of the isotopes of concern. The acquisition system collects spectral information together with the aircraft position and altitude every second. To map ground contamination, a set of scintillation detectors is mounted on an airborne platform (airplane or helicopter) and flown over contaminated areas. Its usefulness was demonstrated extensively during the response to the Fukushima NPP accident in March-May 2011. Airborne gamma spectrometry is one of the primary techniques used to define the extent of ground contamination after a radiological incident.
0 kommentar(er)
